Path Tracing. Michael Doggett Department of Computer Science Lund university Michael Doggett


 Clarence Benson
 3 years ago
 Views:
Transcription
1 Path Tracing Michael Doggett Department of Computer Science Lund university 2012 Michael Doggett
2 Outline Light transport notation Radiometry  Measuring light Illumination Rendering Equation Monte Carlo sampling Russian roulette Path tracing Image based lighting 2011 Michael Doggett
3 This is what we want: Courtesy of Henrik Wann Jensen Courtesy of Paul Debevec Images courtesy of Illuminate Labs 2008 Tomas AkenineMöller!3
4 Isn t Whittedstyle ray tracing enough? Does not give truly realistic images Why? Does not solve the entire rendering equation Miss several phenomenon: Caustics Indirect illumination (color bleeding, ambient lighting) Soft shadows This lecture will present Global Illumination techniques: path tracing and imagebased lighting. Images courtesy of Henrik Wann Jensen University of California San Diego 2008 Tomas AkenineMöller!4
5 Notation after Paul Heckbert, SIGGRAPH 90 Light transport notation Useful tool for thinking about global illumination (GI) Follow light paths The endpoints of straight paths can be: L : light source E : the eye S : a specular reflection D: a diffuse reflection G: semidiffuse (glossy) reflection Regular expressions can be used: (K)+ : one or more of K (K)* : zero or more of K (K)? : zero or one of K (K M) : a K or an M event 2008 Tomas AkenineMöller!5
6 Examples of light transport notation light B A Specular ball eye diffuse floor and wall!path A: LDDDE!Path B: LSDSDE 2008 Tomas AkenineMöller!6
7 Light transport notation: why? The ultimate goal is to simulate all light paths: L(S G D)*E Using this notation, we can find what Whitted ray tracing can handle: LDS*E LS*E = LD?S*E Or if we include glossy surfaces: LD?(G S)*E This is clearly not L(S G D)*E! 2008 Tomas AkenineMöller!7
8 The Rendering Equation It extends the range of optical phenomena which can be effectively simulated. From paper of the same name, The Rendering Equation, by James T. Kajiya, SIGGRAPH Michael Doggett
9 Radiometry Flux (radiant power): [W ] Big Phi The total energy that flows from/to/through a surface Irradiance: E = d da apple W m 2 Incoming radiant power per unit surface area Radiosity (radiant exitance) Same as irradiance but outgoing 2012 Michael Doggett
10 Radiometry Solid Angle, = A r 2 n x Like the 2D version of an angle Shape of grey area doesn t matter Dimensionless expressed in steradians x r A Solid angle of sphere is Michael Doggett
11 x Radiometry Small Theta Radiance: L(x! ) N L L(x >Θ) 5 dimensions: position (x) and direction vector (Θ) Important: captures appearance of objects Flux per unit projected area (E) per unit solid angle da θ dω Small Omega Solid angle  subtends area on hemisphere! θ Incoming flux is spread out over a larger area with bigger angles, the cosine term compensates for this 2012 Michael Doggett
12 Rendering Equation L is radiance = most important quantity  captures appearance of objects in a scene.  what we store in a pixel. Energy conservation  total outgoing radiance at a point is the sum of the emitted and reflected radiance. Incoming  Big Psi BRDF The equation above is the Rendering Equation : most important equation in graphics It is a Fredholm equation of the second kind: L is both to the left, and inside the integral Section 11.6 in book, but it uses a different notation 2008 Tomas AkenineMöller!12
13 Rendering Equation  Lr Why not sample light sources separately? They give most of the appearance (usually)! + Direct illumination 2008 Tomas AkenineMöller Indirect illumination!13
14 Direct Illumination: L direct Some definitions: Is the closest positive intersection along ray that starts at x and has direction Ψ V(x,y) is the visibility function: is 0 if x occluded from y, otherwise 1. Approach: integrate over the light surface area instead of over the hemisphere The geometry term: G(x,y)V(x,y) is often called radiance transfer 2008 Tomas AkenineMöller!14
15 Indirect Illumination The incoming radiance at x in direction Ψ is the same as the outgoing radiance from y in direction Ψ the raycasting operation, finds the closest positive intersection along ray that starts at x and has direction Ψ 2008 Tomas AkenineMöller!15
16 GI illustrated + Direct illumination Indirect illumination Recursion Illustrated: (dashed lines are shadow rays) 2008 Tomas AkenineMöller!16
17 L indirect Change from integrating Cartesian coordinate (solid angle) to (hemi)spherical coordinates: J is the Jacobian of the coordinate transform 2008 Tomas AkenineMöller!17
18 Monte Carlo Integration Need to integrate incoming light over hemisphere Estimate definite integral using random samples Monte Carlo estimate 2011 Michael Doggett
19 Monte Carlo Recap X is stochastic random variable, drawn from PDF p(x) How to evaluate the integral of f(x) when x is drawn from PDF p(x)? x i drawn from PDF See chapter 10 for more explanation Copyright 2008 Tomas AkenineMöller!19
20 Practical direct illumination using MC The PDF, p(y) may be uniform, i.e., 1/A! 2008 Tomas AkenineMöller!20
21 Russian roulette We need to be able to terminate recursion Bias is the error (possibly) introduced with some technique: E[I MC ]I (mean of MC minus real solution) Avoid incorrect lighting contributions (bias) Light bounces around infinitely... How to avoid infinite path lengths without bias? 2008 Tomas AkenineMöller!21
22 Russian roulette for indirect illumination That is, we can stop recursion with a probability of α=1p, where α is the absorption probability If photon not absorbed, diffuse or specular? Random number r from [0,1] If(r < ρ d ) then shoot diffuse ray!  randomly on hemisphere... Else if(r < ρ d +ρ s ) then shoot specular ray Else absorb Use average reflectance E.g., ρ d =(ρ d,red + ρ d,green + ρ d,blue )/3 Or special reflectivity parameter of material As done in programming assignments 2008 Tomas AkenineMöller!22
23 Practical indirect illumination How to choose random direction on the hemisphere? Uniformly distributed Instead: I.e., choose random θ and ϕ, and then use The sin θ to correct for nonuniform distribution Not efficient! 2008 Tomas AkenineMöller!23
24 Importance Sampling Choose the PDF proportional to a factor in the equation that we want to integrate i.e. send more rays near the normal For rendering equation, this can be: cos(ψ i,n x ) Included in programming assignment 3 BRDF Incident radiance Combination Tomas AkenineMöller!24
25 Path tracing algorithm Shoot many rays through each pixel Compute direct illumination Compute indirect illumination (recursive) Use Russian roulette to terminate recursion without bias Use Hemispherical Monte Carlo sampling! Important for path tracing: Shoot one ray to the light sources Shoot one ray over the hemisphere Reason: do not want to spend more rays that are deeper down in the paths 2008 Tomas AkenineMöller!25
26 Conventional Ray Tracing vs. Path Tracing ray path ordinary surfaces light surfaces figure after The Rendering Equation, Jim T. Kajiya, ACM SIGGRAPH Michael Doggett
27 Path tracing example 8 spp 13 sec 200 spp 5 min 1000 spp 25min spp 10.3 hrs From Kevin Beason s GI in 99 lines of C Michael Doggett
28 Image Based Lighting 2012 Michael Doggett
29 ImageBased Lighting Enables very realistic lighting In a simple way Not only primary light sources illuminate a point Basic idea: Capture an image of the environment Each pixel in this image is treated as a light source During rendering, use these lights! 2008 Tomas AkenineMöller!29
30 Example images Images courtesy of Paul Debevec 2008 Tomas AkenineMöller!30
31 More example images Images courtesy of Henrik Wann Jensen 2008 Tomas AkenineMöller!31
32 Capturing environment maps Many ways: (light probes) Take a photograph of a highly reflective sphere Fisheye lens: 2 images needed Special device: rotating image sensors Need high dynamic range images! 3 bytes not enough for RGB " 3 floats Why? Because the range of brightness values is larger than [0,255] 2008 Tomas AkenineMöller!32
33 Example of image with high dynamic range Image courtesy of Paul Debevec Lowest intensity is about 20 Highest intensity is about 12,000 Dynamic range is 1:600! 2008 Tomas AkenineMöller!33
34 High Dynamic Range Images Dynamic range of image: brightest region/dimmest region Very briefly: A digital camera uses a CCD (charge coupled device) array as a sensor. However, these values are mapped, using a nonlinear function in order to display them on screen To recover the entire range of the image, take several photos of the same scene with different exposure times Nonlinear function: from an overdetermined system using SVD Use function to recover HDR image (one float per RGB) There are also cameras that can take 12 bits per color component directly For more details: Debevec & Malik, Recovering High Dynamic Range Radiance Maps from Photographs, SIGGRAPH 97, pp Tomas AkenineMöller!34
35 Example of image with different exposure times Images courtesy of Paul Debevec 2008 Tomas AkenineMöller!35
36 How to capture an image of the environment? Use simplest method: image of highly reflective sphere We get an image of the entire environment, if we can assume that the camera is infinitely far away (or if the sphere is very small) 2008 Tomas AkenineMöller!36
37 Examples of environment maps Dynamic Range: 1:200,000 Images courtesy of Paul Debevec 2008 Tomas AkenineMöller!37
38 How to use environment map Environment map Often need many rays!! May need varying number of rays depending on frequency content of env. map Note: in path tracing, we only shoot one ray at every intersection point, but many rays through each pixel 2008 Tomas AkenineMöller!38
39 HDR file formats EXR ILM 16bit float PFM (Portable Float Map) Public open source Binary, but no compression 2012 Michael Doggett
40 IBL: some notes Even simpler to code with a cube map of the environment Transform sphere map into cube map once before rendering Debevec uses angular map (can use sphere map too) Nice tutorial by Paul Debevec, ImageBased Lighting, IEEE Computer Graphics & Applications, March/April 2002, pp Check out light probe gallery + HDR shop How to do it fast? Agarwal, Ramamoorthi, Belongie and Jensen, Structured Importance Sampling of Environment Maps, SIGGRAPH 2003, pp Probably takes weeks to implement though Tomas AkenineMöller!40
41 Next Friday Lab 2: BVH Next Week Monday Seminar : Path Tracing Lab (Rasmus) Tuesday Lecture : Photon Mapping Guest Lecture, May 12 : Jonas Gustavsson, Sony Production Rendering 2011 Michael Doggett
An introduction to Global Illumination. Tomas AkenineMöller Department of Computer Engineering Chalmers University of Technology
An introduction to Global Illumination Tomas AkenineMöller Department of Computer Engineering Chalmers University of Technology Isn t ray tracing enough? Effects to note in Global Illumination image:
More informationComputer Graphics Global Illumination (2): MonteCarlo Ray Tracing and Photon Mapping. Lecture 15 Taku Komura
Computer Graphics Global Illumination (2): MonteCarlo Ray Tracing and Photon Mapping Lecture 15 Taku Komura In the previous lectures We did ray tracing and radiosity Ray tracing is good to render specular
More informationCSE168 Computer Graphics II, Rendering. Spring 2006 Matthias Zwicker
CSE168 Computer Graphics II, Rendering Spring 2006 Matthias Zwicker Last time Global illumination Light transport notation Path tracing Sampling patterns Reflection vs. rendering equation Reflection equation
More informationpath tracing computer graphics path tracing 2009 fabio pellacini 1
path tracing computer graphics path tracing 2009 fabio pellacini 1 path tracing Monte Carlo algorithm for solving the rendering equation computer graphics path tracing 2009 fabio pellacini 2 solving rendering
More informationMonte Carlo Path Tracing
CS29413: Advanced Computer Graphics Lecture #5 University of California, Berkeley Wednesday, 23 September 29 Monte Carlo Path Tracing Lecture #5: Wednesday, 16 September 29 Lecturer: Ravi Ramamoorthi
More informationCS 431/636 Advanced Rendering Techniques"
CS 431/636 Advanced Rendering Techniques" Dr. David Breen" Korman 105D" Wednesday 6PM 8:50PM" Photon Mapping" 5/2/12" Slide Credits  UC San Diego Goal Efficiently create global illumination images with
More informationAdvanced Computer Graphics. Rendering Equation. Matthias Teschner. Computer Science Department University of Freiburg
Advanced Computer Graphics Rendering Equation Matthias Teschner Computer Science Department University of Freiburg Outline rendering equation Monte Carlo integration sampling of random variables University
More informationPath tracing everything. D.A. Forsyth
Path tracing everything D.A. Forsyth The Rendering Equation 1 We can now write L o (x, ω o )=L e (x, ω o )+ Ω Angle between normal and incoming direction ρ bd (x, ω o, ω i )L i (x, ω i ) cos θ i dω i
More informationPATH TRACING: A NONBIASED SOLUTION TO THE RENDERING EQUATION
PATH TRACING: A NONBIASED SOLUTION TO THE RENDERING EQUATION ROBERT CARR AND BYRON HULCHER Abstract. In this paper we detail the implementation of a path tracing renderer, providing a nonbiased solution
More informationMonte Carlo Path Tracing
HELSINKI UNIVERSITY OF TECHNOLOGY 16.4.2002 Telecommunications Software and Multimedia Laboratory Tik111.500 Seminar on Computer Graphics Spring 2002: Advanced Rendering Techniques Monte Carlo Path Tracing
More informationPHOTON mapping is a practical approach for computing global illumination within complex
7 The Photon Mapping Method I get by with a little help from my friends. John Lennon, 1940 1980 PHOTON mapping is a practical approach for computing global illumination within complex environments. Much
More informationPhoton Mapping Made Easy
Photon Mapping Made Easy Tin Tin Yu, John Lowther and Ching Kuang Shene Department of Computer Science Michigan Technological University Houghton, MI 49931 tiyu,john,shene}@mtu.edu ABSTRACT This paper
More informationRendering Area Sources D.A. Forsyth
Rendering Area Sources D.A. Forsyth Point source model is unphysical Because imagine source surrounded by big sphere, radius R small sphere, radius r each point on each sphere gets exactly the same brightness!
More informationLecture 11: Ray tracing
Interactive Computer Graphics Lecture 11: Ray tracing Graphics Lecture 11: Slide 1 Some slides adopted from H. Pfister, Harvard Graphics Lecture 10: Slide 2 Direct and Global Illumination Direct illumination:
More informationChapter 10. Bidirectional Path Tracing
Chapter 10 Bidirectional Path Tracing In this chapter, we describe a new light transport algorithm called bidirectional path tracing. This algorithm is a direct combination of the ideas in the last two
More informationLighting and Reflectance Models
Lighting and Reflectance Models Basic principles of illumination and reflectance are introduced. They are central to understanding the dependence of image colour and intensity on material reflectance,
More informationMathematics for Global Illumination
Mathematics for Global Illumination Massimo Picardello Mathematics Department, University of Roma Tor Vergata Abstract and disclaimer This is a simple, almost naif approach to the mathematics of global
More informationMetropolis Light Transport. Samuel Donow, Mike Flynn, David Yan CS371 Fall 2014, Morgan McGuire
Metropolis Light Transport Samuel Donow, Mike Flynn, David Yan CS371 Fall 2014, Morgan McGuire Overview of Presentation 1. Description of necessary tools (Path Space, Monte Carlo Integration, Rendering
More informationPrecomputing Lighting in Games. David Larsson Autodesk Inc.
Precomputing Lighting in Games David Larsson Autodesk Inc. What is baked lighting? Precompute lighting information for static scenes and lights Typically baked to Vertices Textures Light probe points
More informationImagebased Lighting in Lightwave 3D
Imagebased Lighting in LightWave Page 1 of 4 Imagebased Lighting in Lightwave 3D 2001 Lightwave 3D Background The Lightwave 3D renderer is one of the most widely used in Film and Broadcast production
More informationINTRODUCTION TO RENDERING TECHNIQUES
INTRODUCTION TO RENDERING TECHNIQUES 22 Mar. 212 Yanir Kleiman What is 3D Graphics? Why 3D? Draw one frame at a time Model only once X 24 frames per second Color / texture only once 15, frames for a feature
More informationIllumination Models and Shading. Foley & Van Dam, Chapter 16
Illumination Models and Shading Foley & Van Dam, Chapter 16 Illumination Models and Shading Light Source Models Ambient Illumination Diffuse Reflection Specular Reflection Polygon Rendering Methods Flat
More informationDhiren Bhatia Carnegie Mellon University
Dhiren Bhatia Carnegie Mellon University University Course Evaluations available online Please Fill! December 4 : Inclass final exam Held during class time All students expected to give final this date
More informationThe RADIANCE Lighting Simulation and Rendering System
The RADIANCE Lighting Simulation and Rendering System Written by Gregory J. Ward Lighting Group Building Technologies Program Lawrence Berkeley Laboratory COMPUTER GRAPHICS Proceedings, Annual Conference
More informationRadiance Caching for Participating Media
Radiance Caching for Participating Media Wojciech Jarosz Craig Donner Matthias Zwicker Henrik Wann Jensen University of California, San Diego Pixel Lab http://mev.fopf.mipt.ru Wojciech Jarosz http://mattmosher.com/
More informationComputer Animation: Art, Science and Criticism
Computer Animation: Art, Science and Criticism Tom Ellman Harry Roseman Lecture 12 Ambient Light Emits two types of light: Directional light, coming from a single point Contributes to diffuse shading.
More informationREALTIME IMAGE BASED LIGHTING FOR OUTDOOR AUGMENTED REALITY UNDER DYNAMICALLY CHANGING ILLUMINATION CONDITIONS
REALTIME IMAGE BASED LIGHTING FOR OUTDOOR AUGMENTED REALITY UNDER DYNAMICALLY CHANGING ILLUMINATION CONDITIONS Tommy Jensen, Mikkel S. Andersen, Claus B. Madsen Laboratory for Computer Vision and Media
More informationThea Omni Light. Thea Spot Light. Light setup & Optimization
Light setup In this tutorial we will learn how to setup lights inside Thea Studio and how to create mesh lights and optimize them for faster rendering with less noise. Let us have a look at the different
More informationPath Tracing  Literature Research. Rick de Bruijne May 17, 2011
Path Tracing  Literature Research Rick de Bruijne May 17, 2011 1 Contents 1 Abstract 3 2 Natural Phenomena 4 2.1 Motion Blur....................................... 4 2.2 Fresnel..........................................
More informationNikolay Stefanov, PhD Ubisoft Massive GLOBAL ILLUMINATION IN GAMES
Nikolay Stefanov, PhD Ubisoft Massive GLOBAL ILLUMINATION IN GAMES What is global illumination? Interaction between light and surfaces Adds effects such as soft contact shadows and colour bleeding Can
More informationRadiosity Rendering. Chapter 5. References. 5.1 Radiosity
Chapter 5 Radiosity Rendering References As you read the following, you may find the following summary helpful. In particular it contains some nice illustrations. http://www.siggraph.org/education/materials/hypergraph/radiosity/radiosity.htm
More informationMonte Carlo Ray Tracing
Monte Carlo Ray Tracing Siggraph 2003 Course 44 Tuesday, July 29, 2003 Organizer Henrik Wann Jensen University of California, San Diego Lecturers James Arvo University of California, Irvine Phil Dutre
More informationShading. Reading. Pinhole camera. Basic 3D graphics. Brian Curless CSE 557 Fall 2013. Required: Shirley, Chapter 10
Reading Required: Shirley, Chapter 10 Shading Brian Curless CSE 557 Fall 2013 1 2 Basic 3D graphics With affine matrices, we can now transform virtual 3D obects in their local coordinate systems into a
More informationGeometric and Radiometric Camera Calibration
Geometric and Radiometric Camera Calibration Shape From Stereo requires geometric knowledge of: Cameras extrinsic parameters, i.e. the geometric relationship between the two cameras. Camera intrinsic parameters,
More informationHigh Dynamic Range and other Fun Shader Tricks. Simon Green
High Dynamic Range and other Fun Shader Tricks Simon Green Demo Group Motto If you can t make it good, make it big. If you can t make it big, make it shiny. Overview The OpenGL vertex program and texture
More informationA Theoretical Framework for Physically Based Rendering
Volume 13, (1994) number 2, pp. 97107 A Theoretical Framework for Physically Based Rendering Eric P. Lafortune and Yves D. Willems Department of Computer Science, Katholieke Universiteit Leuven Celestijnenlaan
More informationA Practical Model for Subsurface Light Transport
A Practical Model for Subsurface Light Transport Henrik Wann Jensen Stephen R. Marschner Marc Levoy Pat Hanrahan Stanford University Abstract This paper introduces a simple model for subsurface light transport
More informationA Ray Tracing Solution for Diffuse Interreflection
A Ray Tracing Solution for Diffuse Interreflection Gregory J. Ward Francis M. Rubinstein Robert D. Clear Lighting Systems Research Lawrence Berkeley Laboratory 1 Cyclotron Rd., 903111 Berkeley, CA 94720
More informationCUBEMAP DATA STRUCTURE FOR INTERACTIVE GLOBAL ILLUMINATION COMPUTATION IN DYNAMIC DIFFUSE ENVIRONMENTS
ICCVG 2002 Zakopane, 2529 Sept. 2002 Rafal Mantiuk (1,2), Sumanta Pattanaik (1), Karol Myszkowski (3) (1) University of Central Florida, USA, (2) Technical University of Szczecin, Poland, (3) Max PlanckInstitut
More informationDigital Image Fundamentals. Selim Aksoy Department of Computer Engineering Bilkent University saksoy@cs.bilkent.edu.tr
Digital Image Fundamentals Selim Aksoy Department of Computer Engineering Bilkent University saksoy@cs.bilkent.edu.tr Imaging process Light reaches surfaces in 3D. Surfaces reflect. Sensor element receives
More informationAishah Abdul Razak Faculty of Information Technology, Multimedia University,63100 Cyberjaya, Selangor, Malaysia
Comparison of High Dynamic Range Images (HDRI) rendering technique with normal rendering for integrating 3D architectural model into 2D local environment Aishah Abdul Razak Faculty of Information Technology,
More informationTreasure Hunt. Lecture 2 How does Light Interact with the Environment? EMR Principles and Properties. EMR and Remote Sensing
Lecture 2 How does Light Interact with the Environment? Treasure Hunt Find and scan all 11 QR codes Choose one to watch / read in detail Post the key points as a reaction to http://www.scoop.it/t/env202502w2
More informationShading. Reading. Pinhole camera. Basic 3D graphics. Brian Curless CSE 557 Fall 2014. Required: Shirley, Chapter 10
Reading Required: Shirley, Chapter 10 Shading Brian Curless CSE 557 Fall 2014 1 2 Basic 3D graphics With affine matrices, we can now transform virtual 3D objects in their local coordinate systems into
More informationVolumetric Path Tracing
Volumetric Path Tracing Steve Marschner Cornell University CS 6630 Spring 2012, 8 March Using Monte Carlo integration is a good, easy way to get correct solutions to the radiative transfer equation. It
More informationAccelerating the bidirectional path tracing algorithm using a dedicated intersection processor
Universität Karlsruhe (TH) Forschungsuniversität  gegründet 1825 Fakultät für Informatik Institut für Betriebs und Dialogsysteme Studienarbeit Accelerating the bidirectional path tracing algorithm using
More informationMeasurement of Lighting
Measurement of Lighting Light is one form of energy and could be measured by the standard units of energy. But the effect of light on the human environment also depends upon the sensitivity of the eye,
More informationSpecular reflection. Dielectrics and Distribution in Ray Tracing. Snell s Law. Ray tracing dielectrics
Specular reflection Dielectrics and Distribution in Ray Tracing CS 465 Lecture 22 Smooth surfaces of pure materials have ideal specular reflection (said this before) Metals (conductors) and dielectrics
More informationCapturing and Simulating Physically Accurate Illumination in Computer Graphics
Capturing and Simulating Physically Accurate Illumination in Computer Graphics PAUL DEBEVEC Institute for Creative Technologies University of Southern California Marina del Rey, California Anyone who has
More informationCourse Overview. CSCI 480 Computer Graphics Lecture 1. Administrative Issues Modeling Animation Rendering OpenGL Programming [Angel Ch.
CSCI 480 Computer Graphics Lecture 1 Course Overview January 14, 2013 Jernej Barbic University of Southern California http://wwwbcf.usc.edu/~jbarbic/cs480s13/ Administrative Issues Modeling Animation
More informationDYNAMIC RANGE IMPROVEMENT THROUGH MULTIPLE EXPOSURES. Mark A. Robertson, Sean Borman, and Robert L. Stevenson
c 1999 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or
More informationIN previous chapters we assumed that all lighting interactions occurred at surfaces. In particular,
4 Light Transport in Participating Media Thus, if one is to be five times as distant, make it five times bluer. Leonardo Da Vinci, 1452 1519 IN previous chapters we assumed that all lighting interactions
More informationA Short Introduction to Computer Graphics
A Short Introduction to Computer Graphics Frédo Durand MIT Laboratory for Computer Science 1 Introduction Chapter I: Basics Although computer graphics is a vast field that encompasses almost any graphical
More informationIntroduction to Computer Graphics
Introduction to Computer Graphics Torsten Möller TASC 8021 7787822215 torsten@sfu.ca www.cs.sfu.ca/~torsten Today What is computer graphics? Contents of this course Syllabus Overview of course topics
More informationGoniometric Light Reconstruction for Augmented Reality Image Synthesis
Goniometric Light Reconstruction for Augmented Reality Image Synthesis Thorsten Grosch Institut für Computervisualistik Universität KoblenzLandau Universitätsstraße 1 D56070 Koblenz grosch@unikoblenz.de
More informationSpherical Harmonic Gradients for MidRange Illumination
Eurographics Symposium on Rendering (2004) H. W. Jensen, A. Keller (Editors) Spherical Harmonic Gradients for MidRange Illumination Thomas Annen 1 Jan Kautz 2 Frédo Durand 2 HansPeter Seidel 1 1 MPI
More informationRadiometry. Steve Marschner Cornell University CS 6630 Spring 2012, 26 January
Radiometry Steve Marschner Cornell University CS 6630 Spring 2012, 26 January Radiometry is a system for describing the flow of radiant energy through space. It is essentially a geometric topic all the
More informationSkillsUSA 2014 Contest Projects 3D Visualization and Animation
SkillsUSA Contest Projects 3D Visualization and Animation Click the Print this Section button above to automatically print the specifications for this contest. Make sure your printer is turned on before
More informationRealtime Volumetric Lighting in Participating Media
EUROGRAPHICS 2009 / P. Alliez and M. Magnor Short Paper Realtime Volumetric Lighting in Participating Media Balázs Tóth and Tamás Umenhoffer, Budapest University of Technology and Economics, Hungary Abstract
More informationINFOGR Computer Graphics. J. Bikker  AprilJuly 2016  Lecture 12: Postprocessing. Welcome!
INFOGR Computer Graphics J. Bikker  AprilJuly 2016  Lecture 12: Postprocessing Welcome! Today s Agenda: The Postprocessing Pipeline Vignetting, Chromatic Aberration Film Grain HDR effects Color Grading
More informationHighresolution Imaging System for Omnidirectional Illuminant Estimation
Highresolution Imaging System for Omnidirectional Illuminant Estimation Shoji Tominaga*, Tsuyoshi Fukuda**, and Akira Kimachi** *Graduate School of Advanced Integration Science, Chiba University, Chiba
More informationCOMP 558 Exercises 1 Oct 2, 2010
Questions 1. When a face is photographed from the front and from a small distance, the nose appears much larger than it should in comparison to the other parts of the face. Why? 2. Below are sketches of
More informationAccurate Light Intensity & Camera Exposure
Accurate light intensity Accurate Light Intensity Camera Exposure One of the benefits when working with a physically based render engine is that we can relay on real world values for our materials, lights
More informationLighting Estimation in Indoor Environments from LowQuality Images
Lighting Estimation in Indoor Environments from LowQuality Images Natalia Neverova, Damien Muselet, Alain Trémeau Laboratoire Hubert Curien UMR CNRS 5516, University Jean Monnet, Rue du Professeur Benoît
More informationImproved predictive modeling of white LEDs with accurate luminescence simulation and practical inputs
Improved predictive modeling of white LEDs with accurate luminescence simulation and practical inputs TracePro OptoMechanical Design Software s Fluorescence Property Utility TracePro s Fluorescence Property
More informationThe Close Objects Buffer: A Sharp Shadow Detection Technique for Radiosity Methods
The Close Objects Buffer: A Sharp Shadow Detection Technique for Radiosity Methods A.C. Telea, C.W.A.M. van Overveld Department of Mathematics and Computing Science Eindhoven University of Technology P.O.
More informationOutdoor beam tracing over undulating terrain
Outdoor beam tracing over undulating terrain Bram de Greve, Tom De Muer, Dick Botteldooren Ghent University, Department of Information Technology, SintPietersNieuwstraat 4, B9000 Ghent, Belgium, {bram.degreve,tom.demuer,dick.botteldooren}@intec.ugent.be,
More informationCAUSTICS are complex patterns of shimmering
SCHOOL OF ENGINEERING AND COMPUTER SCIENCE, UNIVERSITY OF CENTRAL FLORIDA, CS TR 5007 1 Caustics Mapping: An Imagespace Technique for Realtime Caustics Musawir Shah, Sumanta Pattanaik Abstract In this
More informationOptical Design Tools for Backlight Displays
Optical Design Tools for Backlight Displays Introduction Backlights are used for compact, portable, electronic devices with flat panel Liquid Crystal Displays (LCDs) that require illumination from behind.
More informationReflectance Characteristics of Accuflect Light Reflecting Ceramic
Reflectance Characteristics of Accuflect Light Reflecting Ceramic Copyright July 1 Accuratus Corporation 35 Howard Street Phillipsburg, NJ 8865 USA +1.98.13.77 http://accuratus.com SUMMARY Accuflect is
More informationLast Lecture. Single View Modeling. Vermeer s Music Lesson Reconstructions by Criminisi et al.
Last Lecture Single View Modeling Vermeer s Music Lesson Reconstructions by Criminisi et al. Today Photometric Stereo Separate Global and Direct Illumination Photometric Stereo Photometric Stereo Readings
More informationComputer Applications in Textile Engineering. Computer Applications in Textile Engineering
3. Computer Graphics Sungmin Kim http://latam.jnu.ac.kr Computer Graphics Definition Introduction Research field related to the activities that includes graphics as input and output Importance Interactive
More informationIntroduction to Computer Graphics. Jürgen P. Schulze, Ph.D. University of California, San Diego Fall Quarter 2012
CSE 167: Introduction to Computer Graphics Jürgen P. Schulze, Ph.D. University of California, San Diego Fall Quarter 2012 Today Course organization Course overview 2 Course Staff Instructor Jürgen Schulze,
More informationRay Optics Minicourse COMSOL Tokyo Conference 2014
Ray Optics Minicourse COMSOL Tokyo Conference 2014 What is the Ray Optics Module? Addon to COMSOL Multiphysics Can be combined with any other COMSOL Multiphysics Module Includes one physics interface,
More informationVARIANCE REDUCTION TECHNIQUES FOR IMPLICIT MONTE CARLO SIMULATIONS
VARIANCE REDUCTION TECHNIQUES FOR IMPLICIT MONTE CARLO SIMULATIONS An Undergraduate Research Scholars Thesis by JACOB TAYLOR LANDMAN Submitted to Honors and Undergraduate Research Texas A&M University
More informationConvention Paper Presented at the 118th Convention 2005 May 28 31 Barcelona, Spain
Audio Engineering Society Convention Paper Presented at the 118th Convention 2005 May 28 31 Barcelona, Spain This convention paper has been reproduced from the author s advance manuscript, without editing,
More informationHi everyone, my name is Michał Iwanicki. I m an engine programmer at Naughty Dog and this talk is entitled: Lighting technology of The Last of Us,
Hi everyone, my name is Michał Iwanicki. I m an engine programmer at Naughty Dog and this talk is entitled: Lighting technology of The Last of Us, but I should have called it old lightmaps new tricks 1
More informationEfficient Illumination by High Dynamic Range Images
Eurographics Symposium on Rendering 23 Per Christensen and Daniel CohenOr (Editors) Efficient Illumination by High Dynamic Range Images Thomas Kollig 1 and Alexander Keller 2 1 Department of Computer
More informationArchitecture of a Graphics Pipeline. 6 February 2007 CMPT370 Dr. Sean Ho Trinity Western University
Architecture of a Graphics Pipeline 6 February 2007 CMPT370 Dr. Sean Ho Trinity Western University Review last time Visual computing: Computer graphics and image analysis Objectives of visual computing
More informationRay Tracing with Cones
Ray Tracing with Cones John Amanatides Department of Computer Science University of Toronto Toronto, Canada M5S 1A4 Abstract A new approach to ray tracing is introduced. The definition of a "ray" is extended
More informationInteractions Between Electromagnetic Wave and Targets
Interactions Between Electromagnetic Wave and Targets Electromagnetic radiation wavelength λ, frequency ν and the velocity υ have the following relation. λ = υ/ν by: Dr. Kiyoshi Honda Space Technology
More informationCS 563 Advanced Topics in Computer Graphics Russian Roulette  Sampling Reflectance Functions by Alex White
CS 563 Advanced Topics in Computer Graphics Russian Roulette  Sampling Reflectance Functions by Alex White Monte Carlo Ray Tracing Monte Carlo In ray tracing, use randomness to evaluate higher dimensional
More informationBooks. CS155b Computer Graphics. Homework. Additional References. Syllabus. Goals
CS155b Computer Graphics Instructor: Giovanni Motta (gim@ieee.org) Volen, Room #255. Phone: x62718 Class: Mon. and Wed. from 5 to 6:30pm Abelson #131 Teaching Assistants: Anthony Bucci (abucci@cs) John
More informationDeferred Shading & Screen Space Effects
Deferred Shading & Screen Space Effects State of the Art Rendering Techniques used in the 3D Games Industry Sebastian Lehmann 11. Februar 2014 FREESTYLE PROJECT GRAPHICS PROGRAMMING LAB CHAIR OF COMPUTER
More informationLezione 4: Grafica 3D*(II)
Lezione 4: Grafica 3D*(II) Informatica Multimediale Docente: Umberto Castellani *I lucidi sono tratti da una lezione di Maura Melotti (m.melotti@cineca.it) RENDERING Rendering What is rendering? Rendering
More informationShading with Shaders. Computer Graphics, VT 2015 Lecture 6
Shading with Shaders Computer Graphics, VT 2015 Lecture 6 Johan Nysjö Centre for Image analysis Swedish University of Agricultural Sciences Uppsala University Today's topics Shading in modern OpenGL Pervertex
More informationRay Casting. Simplest shading approach is to perform independent lighting calculation for every pixel
Ray Casting Simplest shading approach is to perform independent lighting calculation for every pixel ) ) ( ) ( ( + + + = i i n i S i i D AL A E I R V K I L N K I K I I Polygon Rendering Methods Given a
More informationIntroduction to Computer Vision. Week 11, Fall 2010 Instructor: Prof. Ko Nishino
Introduction to Computer Vision Week 11, Fall 2010 Instructor: Prof. Ko Nishino The Projective Plane Why do we need homogeneous coordinates? represent points at infinity, homographies, perspective projection,
More informationBlender Notes. Introduction to Digital Modelling and Animation in Design Blender Tutorial  week 9 The Game Engine
Blender Notes Introduction to Digital Modelling and Animation in Design Blender Tutorial  week 9 The Game Engine The Blender Game Engine This week we will have an introduction to the Game Engine build
More informationMCRT: L6. Initial weight of packet: W = L / N MC At each interaction multiply weight by probability of scattering: W = a W
MCRT: L6 Variance reduction techniques improve signaltonoise of simulation using same number of MC packets Examples of where MCRT is inefficient optically thin (need lots of photons) Weights keep packet
More informationContents Rendering Reference
Contents 1 Rendering Reference 6 1.1 Render Type...................................... 6 1.2 Sampling........................................ 7 1.2.1 AntiAliasing................................. 7 1.2.2
More informationSensor Modeling for a Walking Robot Simulation. 1 Introduction
Sensor Modeling for a Walking Robot Simulation L. France, A. Girault, JD. Gascuel, B. Espiau INRIA, Grenoble, FRANCE imagis, GRAVIR/IMAG, Grenoble, FRANCE Abstract This paper proposes models of shortrange
More informationABS 731 Lighting Design & Technology. Spring 2006
ABS 731 Lighting Design & Technology Spring 2006 AGI32 is used to predict the photometric performance of selected luminaires or daylight penetration in a simulated environment. The environments that can
More informationIntroduction to Spectral Reflectance (passive sensors) Overview. Electromagnetic Radiation (light) 4/4/2014
Introduction to Spectral Reflectance (passive sensors) Kelly R. Thorp Research Agricultural Engineer USDAARS AridLand Agricultural Research Center Overview Electromagnetic Radiation (light) Solar Energy
More informationLecture on Solid Angle
Lecture on Solid Angle Ben Kravitz 1 Introduction The idea of a solid angle comes up a lot in remote sensing applications, so it s important that you know what it is. As such, I ve made this lecture for
More informationCSE168 Computer Graphics II, Rendering. Spring 2006 Matthias Zwicker
CSE168 Computer Graphics II, Rendering Spring 2006 Matthias Zwicker Last time Sampling and aliasing Aliasing Moire patterns Aliasing Sufficiently sampled Insufficiently sampled [R. Cook ] Fourier analysis
More informationSimulating Multiple Scattering in Hair Using a Photon Mapping Approach
Simulating Multiple Scattering in Hair Using a Photon Mapping Approach Jonathan T. Moon Stephen R. Marschner Program of Computer Graphics Cornell University Abstract Simulating multiple scattering correctly
More informationPhysical properties of light
Physical properties of light Physical properties of light Light consists of photons particles with no mass which travel at the speed of light Physical properties of light Light consists of photons particles
More informationHow Landsat Images are Made
How Landsat Images are Made Presentation by: NASA s Landsat Education and Public Outreach team June 2006 1 More than just a pretty picture Landsat makes pretty weird looking maps, and it isn t always easy
More informationSpecific Intensity. I ν =
Specific Intensity Initial question: A number of active galactic nuclei display jets, that is, long, nearly linear, structures that can extend for hundreds of kiloparsecs. Many have two oppositelydirected
More informationCS 87/187, Spring Monte Carlo II: Improved Sampling & Variance Reduction. Random Stratified NRooks
CS 87/187, Spring 2016 RENDERING ALGORITHMS Monte Carlo II: Improved Sampling & Variance Reduction Random Stratified NRooks Ansel Adams MultiJittered QuasiRandom PoissonDisc Prof. Wojciech Jarosz wojciech.k.jarosz@dartmouth.edu
More information